textproduct: Rapid City

KEY MESSAGES

- Tonight and Sunday: Cold with flurries and light snow

- Monday: Warmer

- This Week: Dry and mild

DISCUSSION

(This Evening Through Saturday) Issued at 114 PM MST Sat Jan 24 2026

Upper level analysis has a broad area of low pressure over Ontario with a trough extending southwestward toward southern California. Additionally, there is the very strong low pressure system over northern Mexico that will eject across the Southern Plains into the Appalachians and then into the Northeast and Mid-Atlantic States this weekend. Water vapor imagery has a weak shortwave pushing southeastward through northern Wyoming, with a stronger shortwave moving through central Montana. At the surface, a large area of high pressure is over the Great Lakes area with a frontal boundary extending down the Rockies from Alberta to eastern Wyoming and through central Colorado, and a cold front extending from Ontario through southern Canada to Alberta.

For tonight, a reinforcing shot of arctic air will accompany the shortwave moving through central Montana and the Canadian cold front as it moves through the Northern Plains. Frontogenesis associated with these features will result in some flurries and light snow. Upslope enhancement across the northern Black Hills could result in an inch or so of dry, powdery snow. Temperatures will once again fall below zero across the entire forecast area. Winds will mainly be 5 to 15 mph from the north/northwest, with slightly stronger winds of 10 to 20 mph across the western South Dakota Plains. Wind chills are expected to drop to -10F (Black Hills) to -30F (far northwestern South Dakota), late tonight into Sunday morning. Threshold for cold weather advisory is below -25F for most of the area and below -30F for northwest South Dakota, thus no highlights are expected.

Temperatures will remain cold on Sunday as surface high pressure sinks southward from Canada. Highs will struggles to reach the single digits above zero and the lower teens. North/northwest winds of 10 to 20 mph, strongest over the western South Dakota plains, will result in wind chills of -10F to -20F.

Strong warm air advection begins Sunday night and continues into Monday, bringing an impressive overnight warm up. 850mb temperatures climb from -20C at 0Z Sunday to around 0C by 18Z Monday. Highs Monday will be in the 30s and 40s, resulting in a 24 hour temperature change of 30F to 40F degrees. A weak cold front moves through late Monday and Monday evening, but the strongest frontogenesis is over Minnesota and the eastern Dakotas. Thus, the main impact will be gusty west to northwest winds over the plains of western and south central South Dakota.

Upper level high pressure will build over the Rockies this week, shifting into the western High Plains by late week. 850mb temperatures of 0C to -5C, will result in surface temperatures near seasonal averages for late January.

AVIATION

(For the 00Z TAFS Through 00Z Sunday Evening) Issued At 351 PM MST Sat Jan 24 2026

VFR conditions will persist this afternoon into the evening hours. Incoming cold front will bring a wind shift to the north- northwest and the chance for some -SN across the KGCC terminal. Winds will be around 15 knots with gusts up to 30 knots at the KRAP terminal expected to begin by 05z. At KGCC, -SN between 03-06z will bring the chance for some MVFR/IFR conditions.

FIRE WEATHER

Issued At 114 PM MST Sat Jan 24 2026

There will be an elevated risk for near critical fire weather conditions on Monday across portions of the plains due to gusty west to northwest winds of 15 to 30 mph and gusts up to 50 mph, limited snow cover, and the warmer conditions.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.